Keyhole-guard.



No. 784,947. PATBNTBD MAR.,14, 1905.

` J, KoHoUsEK.

KEYHOLB GUARD. APPLIOATION FILED MAB. 12, i904.

@JWM Fil/ f @Jkwwwug Patented March 14, 1905.

PATENT FFICE.

JOSEF KOHOUSEK, OF BUDAPEST, AUSTRlAJlUNGARY.

KEYHOLE-GUARD.

SPECIFICATION forming part of Letters Patent No. 784,947, dated March 14, 1905.

Application iled March l2, 1904. Serial No. 198,085.

To r/.ZZ Ylul/,011?, rif; may concern:

Be it known that l, Josnr KoHoUsEK, eng-- neer, residing at 55 ll/Iargitkrut, Budapest, in the Empire of Austria-Hungary, have invented a new and useful Keyhole Guard or Closing Device, of which the following is a specification.

This invention relates to a keyhole guard or closing devicethat is to say, to a safety device for blocking' the keyhole-so that after the said device has been introduced into the keyhole and locked it is no longer possible to introduce another key and to open the lock or to obtain a wax impression of the keyhole for the purpose of forging a key.

Such devices mainly consist,as is well known, of a safety-lock of the shape corresponding to that of the keyhole, said lock after having been opened by means of a special key being introduced completely into the keyhole in such manner that after it has been locked it cannot be withdrawn by means of another key or any other object or pushed in or turned in the hole. The key of the lock can be withdrawn from the keyhole when the lock'is open only together with the whole device. The keyhole of the device serving to receive the key is always inaccessible, so that an imitation of this key cannot be forged.

The safety-lock used in this keyhole-closing device consists according to this invention of a keyhole-guard, consisting' of ahousing having' substantially the form of the bit and adjacent parts of thc stem of the lock-key, a latch mounted to slide in said housing' and adapted to be projected out at the back of the stem opposite the bit, a movable member mounted in the front of the bit part of said housing and suitably coupled to the said latch, the'adjacent end of the stem part of the said housing' being bored and slotted to receive a key, and means in connection with the said movable member for operating it to project the latch by means of the inserted key, together with other novel features appearing more fully hereinafter and recited in the appended claims.

In the accompanying drawings, Figure l shows a device according to this invention in section in open position--that is to say, in

which it can be introduced into the keyhole. Fig. 2 is a right-hand side view of Fig. 1. Fig. 3 is a section of the device similar to that in Fig. l with the key withdrawn in closed position. Fig. 4 is a front elevation of Fig. 1 with the casing inclosing the lock omitted. Fig. 5 is a section on the line 5 5 of Fig. 1. Fig. 6 is a front elevation similar to that in Fig. 4 with the tumblers partly removed in closed position. Fig. 7 isa section similar to that in Fig. 5 on the line 7 7 of Fig'. 3. Fig'. 8 shows in side elevation the device introduced into the keyhole with the door and doorlock casing in section. Figs. 9 and 10 show, respectively, a front elevation and section similar to Figs. 6 and 3 of a construction of the device according to this invention with a rotating disk instead of a slide.

As will be seen from the drawings, the device consists of a cylindrical bolt 1, corresponding in diameter to the stem of the door-key,

and of a rectangular block 2, connected to it. The latter is intended to receive the locking device and is provided with a casing 4, Fig. 1, which lits exactly into the opening of the escutcheon or plate 3, covering the keyhole, Fig. 8. At one end the bolt 1 is provided with a central bore for receiving the key 5 and with a longitudinal slot 7, Fig. 4, for the introduction of the key-bit 6, the slot 7 being continued at the bottom by a transverse slot 8, Fig. 1, for the purpose of enabling' the key to be turned. The bolt 1 is provided in the middle with an opening', such as the I-shaped opening shown in Fig'. 9, and in the said opening is adjustably mounted a latch 9. One arm 9 of the latch 9 extends into a recess in the block 2 and is provided on its surface with an oblique or cam groove 10, with which engages a pin 12, secured to the bottom of a slide 11, guided in dovetail grooves in thc block 2. Instead of the slide 11 guided in dovetail guides a disk 11, rotatably mounted in the block 2, could be used, as shown in Figs. 9 and 10. The slide or the disk 11 is provided laterally with a recess 13, with which the key-bit engages when turned for the purpose of shifting' or turning the slide or the disk 11. For insuring safety, however, the slide or the disk can move in the usual manner, fixed tumblers 14, of which the drawings show, by way otexample, only two, though of course any desired number could be used, by means of the correspondingly-shaped keybit 6 against the action olf the springs 17, pressing the lateral wall of the recess 15 of the tumblers 111 against the pin 16 ol the slide or of the disk 11. Owing to this rectilinear movement of the slide or to the turning of the disk 11, the pin 12 of the latter will move in the cam-g'roove 10, Fig. 5, oi' the latch 9 and bring the latter, according to the direction in which the key is turned, into the open or closed position. (Shown in Figs. 1, 3, or 10.) In the position or rest the latch 9 is in the position shown in Figs. 3 and 19A-*that is to say, the projection 9 of the latch 9 projects from the surface of the boli'J 1. Then the key 5 can be freely introduced into the safety device, Fig. 6. By turning the key 5 the projection 92 of the latch 9 is completely withdrawn in the manner described into the transverse opening' in the bolt 1, Fig. 1. Then the device can be easily introduced into the keyhole to be locked; but the key 5 cannot for the present be withdrawn from the device, as the bit G is no longer opposite the slot 7. By turning' the key the device is locked in the interior of the keyhole, Fig. 8, and after the projection 92 of the latch 9 has engaged behind the cover-plate 18 of the door-lock casing, and thus become fixed, the key 5 can be withdrawn, the device itself remaining in the keyhole, Fig. 8, thus preventing the opening' of the door-lock from either side. Nhen the key 5 is again introduced and correspondingly turned, the projection 9 of the latch 9 is withdrawn in the manner described into the intelrior of the bolt 1, and the device can then be removed by means of the key-bit 6, which is then in the transverse slot 8. In order to insure still better the safety device against turning', the Jfront end of the bleek 2 is provided with a pin 19, engaging in a lole in the lower part of the cover-plate 18 of the door-lock casing'.

l hat I claim, and desire to secure by Letters Patent of the United States, is-

1. A keyhole-guard consisting of a housing, having' substantially the form of the bit and adjacent parts of the stem of the lock-key, a latch mounted to slide in said housing and adapted to be projected out at the back of the stem opposite the bit, a movable member mounted in the front of the bit part of said housing' and suitably coupled to the said latch, the adjacent end of the stem part of the said housing being bored and slotted to receive a key and means in connection with the said movable member for operating it to project the latch by means of the inserted key substantially as described.

2. A keyhole-guard consisting of a housing having' substantially the form of the bit and adjacent parts of the stem oi' the lock-key, a latch 9 having' projection 92 mounted to slide in said housing and adapted to be projected out ol the same at the back or' the bit part ot' the housing, a diagonal groove 10 in the front part of said latch, a slide 11 having' downwardly-extending pin to engage said groove, a series of tumblers to control the movement of said slide, the adjacent stem part of the housing being' bored and-slotted to allow a key access to the said tu mblers to operate the latch in the manner and for the purpose substantially as described.

In testimony whereof 1 aiHX my signature in presence of two witnesses.

JOSEF KOHOUSEK.

Witnesses:

JOSEF VIEKMANN, Louis VANDoRN. 

